[clang-format] Revert breaking stream operators to previous default (#89016)

Reverts commit d68826d, which changes the previous default behavior of always breaking before a stream insertion operator `<<` if both operands are string literals. Also reverts the related commits 27f5479 and bf05be5. See the discussion in #88483.

Author: owenca

clang/lib/Format/TokenAnnotator.cpp

@@ -5595,12 +5595,8 @@ bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
  return true;
  if (Left.IsUnterminatedLiteral)
  return true;
- // FIXME: Breaking after newlines seems useful in general. Turn this into an
- // option and recognize more cases like endl etc, and break independent of
- // what comes after operator lessless.
- if (Right.is(tok::lessless) && Right.Next &&
- Right.Next->is(tok::string_literal) && Left.is(tok::string_literal) &&
- Left.TokenText.ends_with("\\n\"")) {
+ if (Right.is(tok::lessless) && Right.Next && Left.is(tok::string_literal) &&
+ Right.Next->is(tok::string_literal)) {
  return true;
  }
  if (Right.is(TT_RequiresClause)) {

clang/unittests/Format/FormatTest.cpp

@@ -27339,12 +27339,6 @@ TEST_F(FormatTest, PPDirectivesAndCommentsInBracedInit) {
  getLLVMStyleWithColumns(30));
 }
 
-TEST_F(FormatTest, StreamOutputOperator) {
- verifyFormat("std::cout << \"foo\" << \"bar\" << baz;");
- verifyFormat("std::cout << \"foo\\n\"\n"
- " << \"bar\";");
-}
-
 TEST_F(FormatTest, BreakAdjacentStringLiterals) {
  constexpr StringRef Code{
  "return \"Code\" \"\\0\\52\\26\\55\\55\\0\" \"x013\" \"\\02\\xBA\";"};
@@ -27359,6 +27353,7 @@ TEST_F(FormatTest, BreakAdjacentStringLiterals) {
  Style.BreakAdjacentStringLiterals = false;
  verifyFormat(Code, Style);
 }
+
 } // namespace
 } // namespace test
 } // namespace format

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -2841,15 +2841,6 @@ TEST_F(TokenAnnotatorTest, BraceKind) {
  EXPECT_BRACE_KIND(Tokens[16], BK_BracedInit);
 }
 
-TEST_F(TokenAnnotatorTest, StreamOperator) {
- auto Tokens = annotate("\"foo\\n\" << aux << \"foo\\n\" << \"foo\";");
- ASSERT_EQ(Tokens.size(), 9u) << Tokens;
- EXPECT_FALSE(Tokens[1]->MustBreakBefore);
- EXPECT_FALSE(Tokens[3]->MustBreakBefore);
- // Only break between string literals if the former ends with \n.
- EXPECT_TRUE(Tokens[5]->MustBreakBefore);
-}
-
 TEST_F(TokenAnnotatorTest, UnderstandsElaboratedTypeSpecifier) {
  auto Tokens = annotate("auto foo() -> enum En {}");
  ASSERT_EQ(Tokens.size(), 10u) << Tokens;

polly/lib/Analysis/DependenceInfo.cpp

@@ -951,8 +951,8 @@ class DependenceInfoPrinterLegacyPass final : public ScopPass {
  bool runOnScop(Scop &S) override {
  DependenceInfo &P = getAnalysis<DependenceInfo>();
 
- OS << "Printing analysis '" << P.getPassName() << "' for " << "region: '"
- << S.getRegion().getNameStr() << "' in function '"
+ OS << "Printing analysis '" << P.getPassName() << "' for "
+ << "region: '" << S.getRegion().getNameStr() << "' in function '"
  << S.getFunction().getName() << "':\n";
  P.printScop(OS, S);
 

polly/lib/Analysis/ScopBuilder.cpp

@@ -2715,9 +2715,10 @@ void ScopBuilder::addUserContext() {
  if (NameContext != NameUserContext) {
  std::string SpaceStr = stringFromIslObj(Space, "null");
  errs() << "Error: the name of dimension " << i
- << " provided in -polly-context " << "is '" << NameUserContext
- << "', but the name in the computed " << "context is '"
- << NameContext << "'. Due to this name mismatch, "
+ << " provided in -polly-context "
+ << "is '" << NameUserContext << "', but the name in the computed "
+ << "context is '" << NameContext
+ << "'. Due to this name mismatch, "
  << "the -polly-context option is ignored. Please provide "
  << "the context in the parameter space: " << SpaceStr << ".\n";
  return;